This is part of the disclosure debate that's been going on in the security industry for decades now. Some people take an aggressive full-disclosure stance and believe every flaw should be publicized immediately and some take a non-disclosure stance and say flaws should never be published until they've become entirely irrelevant.
Most have come to the middle and settled on a "responsible disclosure" paradigm, where researchers notify the maintainers and work with them to set a reasonable timeline for the correction of the issue. The issue is publicly disclosed somewhere between 30-90 days after the private disclosure to maintainers; this gives them time to correct the issue and push out updates, and it also incentivizes them to fix the issue instead of sitting on it forever and allowing it to be exploited as a zero-day.
It would've been good to see this paradigm applied here; the search could've sent a message to the repository owner with a note that the result would become public in 60 days, and to ensure all keys had been rotated and that secrets were no longer stored in git after that point.
In any case, none of these people are operating from a morally dubious perspective. I would suggest you refrain from impugning their motives. Virtually everyone in the security community has the end goal of promoting secure software. Aggressive full disclosure advocates believe that their methods will work most effectively not only at getting issues that exist fixed ASAP, but also at ensuring companies adopt strong and safe practices moving forward, since there won't be second chances.